Omron CP1L - Page 146

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Wiring CP1L CPU Units Section 3-4
• If one phase of the power supply is grounded, connect the grounded
phase to the L2/N terminal.
• The GR terminal is a ground terminal. To prevent electrical shock, use a
dedicated ground line (2 mm
2
min.) of 100 Ω or less.
• The line ground terminal (LG) is a noise-filtered neutral terminal. If noise
is a significant source of errors or if electrical shocks are a problem, con-
nect the line ground terminal (LG) to the ground terminal (GR) and ground
both with a ground resistance of 100 Ω or less.
• To prevent electrical shock when short-circuiting between the LG and GR
terminals, always use a ground of 100 Ω or less.
• Do not connect ground lines to other devices or to the frame of a building.
Doing so will reverse the effectiveness of the ground and instead have a
bad influence.
Isolating Transformer The PLC's internal noise control is sufficient for the general noise to which
power supply lines are subjected. Ground noise can be further reduced by
providing the power supply through a 1:1 isolating transformer. Leave the iso-
lating transformer's secondary side ungrounded.
CPU Units with DC Power Supply
DC Power Supply Wiring
• Use crimp terminals or solid wire for wiring the power supply. Do not con-
nect bare stranded wires directly to terminals.
• M3 self-rising terminal screws are used. Tighten the terminal screws to
the torque of 0.5 N·m.
• To prevent noise, use a ground of 100 Ω or less.
DC Power Supply
• Provide a power supply of 20.4 to 26.4 VDC.
• The maximum current consumption is 20 W for CPU Units with 30, 40 or
60 I/O points and 13 W for CPU Units with 10, 14 or 20 I/O points.
• When the power supply is turned ON, the inrush current is approximately
five times the normal current.
• The GR terminal is a ground terminal. To prevent electrical shock, use a
dedicated ground line (2 mm
2
min.) of 100 Ω or less.
Note (1) Never reverse the positive and negative leads when wiring the power sup-
ply terminals.
+ − COM 01 03 05 07 09 11 01 03 05 07 09 11
NC 00 02 04 06 08 10 00 02 04 06 08 10
−
+
24 VDC
Circuit protector
Upper terminal block
Ground (100 Ω or less)
GR: Protective ground terminal
6.2 mm max.
6.2 mm max.